1. Field of the Invention
The present invention relates to an electronic device, and more particularly to an electronic device having display means for representing a dot matrix.
2. Related Background Art
Conventionally, electronic devices such as a electronic notebook, a word processor or a personal computer using a liquid crystal or plasma display as display means are well known, in which so-called automatic power off control is often used where if there is no input such as an operational instruction for a predetermined time, the power supply is turned off for a display unit or the whole electronic device to save the power.
However, in the electronic devices as above described, when it is desired to think while watching the screen without input for a certain time, or watch the information displayed on the screen at times, it is very inconvenient that the screen disappears in a fixed time.
Also, in the type of automatically turning off the power of the whole device, the operation must be restarted from the beginning by turning on the power, which will take some labor and time.
On the other hand, in the type of stopping only the screen display, such a problem may not arise in that an original screen can be restored by the keyboard operation, but there was a disadvantage that a person except for the operator could not know the operation state of the device or the on/off state of power supply.
However, such a method may be very inconvenient when it is desired to think while watching the screen without input such as an operational instruction for a certain time, or watch the information displayed on the screen at times. Also, in the type of automatically turning off the power supply of the whole device, there is the disadvantage that to operate the device again after turning the power off, the operation from the power on to the display of necessary screen must be performed again. The device in which only the screen is turned off can restore the screen with the input from the keyboard, but there is a problem that the operation state of the device or the on/off state of power supply could not be known to a person except for the user, only by glancing at the screen, while the screen was being turned off.